The ghosts appearing and the room freaking out is an actual feature of the game. This will occur in every room you're in unless you move on to the next room in time. You can't kill the ghosts, either, believe me I tried:D.

The hour glass power-up comes in two flavors: one that you can use repeatedly and the one that gets used immediately. The latter has a 50-50 chance of making the ghosts spawn right there and then or extend your time in a given room. Also, I noticed that the hour glass that gets used right away looks no different from the one that makes ghosts spawn immediately so it's a bit of a gamble :D

Don't waste your time or money as they are invincible. They are meant to be ran away from :D.

Just a minor correction on the hourglasses: there IS a difference between the good power-up and the bad one. The good one is sort of green and the bad one is a bit on the red side. I just realized that now :D